SA 387 Gr.22 Cl.2 refers to an ASTM A387 Grade 22 Class 2 chromium-molybdenum alloy steel plate, SA 387 GR.22 CL.2 PLATE is having chromium of 2.25% and molybdenum of 1% and ability to work in 600 Deg C temperatures surrounding effectively. The molybdenum and chromium steel plates are working effectively at different temperature continually offering best performance. The addition of molybdenum in SA 387 alloy is increasing the tensile strength of the plates at greater temperature. Also, it is providing excellent corrosion resistance ability and oxidation as well by increasing the lattice strain. This is effectively stopping the corrosive agent from iron dissolving and gives good heat resistance ability and becomes a good choice for gas surrounding. Also, it has good weldability. Thus, this plate is highly demanded globally.
Specifications for ASME SA387 Grade 22 Alloy Steel Plates
| Designation | Nominal Chromium Content (%) |
Nominal Molybdenum Content (%) |
| SA387 Grade 22 | 2.25% | 1.00% |
Tensile Requirements for ASME SA387 Grade 22 Alloy Steel Plates Class 2 Plates
| Designation: | Requirement: | Grade 22 |
| SA387 Grade 22 | Tensile strength, ksi [MPA] | 75 to 100 [515 to 690] |
| Yield strength, min, ksi [MPa]/(0.2% offset) | 45 [310] | |
| Elongation in 8 in. [200mm], min % | ... | |
| Elongation in 2 in. [50mm], min, % | 18 | |
| Reduction of area, min % | 45 (measured on round specimen) 40 (measured on flat specimen) |
Chemical Requirements for ASME SA387 Grade 22 Alloy Steel Plates
| Element | Chemical Composition (%) | |
| SA387 Grade 22 | ||
| Carbon: | Heat Analysis: | 0.05 - 0.15 |
| Product Analysis: | 0.04 - 0.15 | |
| Manganese: | Heat Analysis: | 0.30 - 0.60 |
| Product Analysis: | 0.25 - 0.66 | |
| Phosphorus: | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Sulphur (max): | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Silicon: | Heat Analysis: | 0.50 max |
| Product Analysis: | 0.50 max | |
| Chromium: | Heat Analysis: | 2.00 - 2.50 |
| Product Analysis: | 1.88 - 2.62 | |
| Molybdenum: | Heat Analysis: | 0.90 - 1.10 |
| Product Analysis: | 0.85 - 1.15 |
Key Applications and Industries Relying on SA 387 Grade 22 Class 2
ASTM A387 GR 22 CL 2 Alloy Steel Plates apply in many industries and general purposes such as food processing, oil & gas, marine, petrochemical, and gas processing industries.
The ASTM A387 GR 22 CL 2 Alloy Steel Plates its use many Industries such as Pressure Vessel Ideal for manufacturing pressure vessels that operate at elevated temperatures, such as those used in the chemical and petrochemical industries and Boiler Commonly used in the construction of boilers and heat exchangers, where the material's high-temperature strength and resistance to oxidation are critical and Power Generation Utilized in power plants for components such as steam headers and turbine casings, which require reliable performance under high thermal stress and Oil and Gas Industry Used in the fabrication of piping systems, reactors, and storage tanks that must withstand harsh environments and high pressures.
Testing of the plates of SA 387 Grade 22 Class 2
Various testing is essentially given greater importance by the producers in order to make sure that the supplied plates are free of errors. The testing is done by the expert by effectively making use of available latest and modern tools. The tests done are positive material identification test, hardness test, intergranular corrosion test, flattening/flaring test, macro/micro test, chemical analysis, pitting resistance test and mechanical test.
Guidelines for Working with SA 387 Grade 22 Class 2
Alloy Steel plates are used extensively in various industries due to their superior mechanical properties and resistance to wear, corrosion, and high temperatures. When a company start the assemble or manufacturing some product or and assemble purpose so that it company has to follow some rules and regulations such as Material Selection and Design and Specification and Fabrication Welding or Quality Control and Testing or Corrosion Protection , Maintenance and Inspection, Safety and Compliance, and Environmental Considerations company has to strictly follows all this object Here are some comprehensive guidelines to ensure their effective and safe use in industrial applications
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What is SA 387 Grade 22 Class 2?
SA 387 Grade 22 Class 2 is a chromium-molybdenum alloy steel plate specified in ASTM A387/A387M, primarily used for pressure vessel and boiler applications requiring good creep strength and heat resistance.
What is the typical chemical composition of SA 387 Gr. 22 Cl. 2?
It generally contains around 2.00% chromium, 1.00% molybdenum, along with controlled amounts of carbon, manganese, silicon, phosphorus, and sulfur. The exact composition must comply with the limits specified in ASTM A387/A387M.
What are the mechanical properties of SA 387 Gr. 22 Cl. 2?
Typical properties include a minimum tensile strength of 415–585 MPa, a minimum yield strength of 205 MPa, and an elongation of 22% minimum. Class 2 requires additional impact testing at lower temperatures compared to Class 1.
What is the difference between SA 387 Gr. 22 Class 1 and Class 2?
The main difference is in impact toughness requirements. Class 2 requires Charpy V-notch impact testing at a lower temperature (usually 0°F or -18°C), ensuring better toughness for more demanding applications.
What is the maximum thickness for SA 387 Gr. 22 Cl. 2 plates?
The standard allows for various thicknesses, but common maximums are around 150 mm or more, depending on the manufacturer's capability and heat treatment requirements.
How does SA 387 Gr. 22 Cl. 2 differ from SA 387 Gr. 11 Cl. 2?
SA 387 Gr. 22 Cl. 2 is a 2.25Cr-1Mo steel, while SA 387 Gr. 11 Cl. 2 is a 1.25Cr-0.5Mo steel. The higher chromium and molybdenum content in Gr. 22 provides significantly better high-temperature strength, creep resistance, and oxidation resistance, especially in long-term service above 500°C. This makes Gr. 22 more suitable for refinery heaters, reformers, and high-temperature reactors, whereas Gr. 11 is often used in less severe temperature conditions. Additionally, Gr. 22 typically requires higher preheat and PWHT during welding due to its higher hardenability.
What is the toughness difference between SA 387 Gr. 22 Cl. 1 and Cl. 2?
The key difference lies in the Charpy V-notch impact requirements. SA 387 Gr. 22 Cl. 2 must meet stricter impact toughness criteria at a lower temperature (usually 0°F or -18°C), whereas Cl. 1 is tested at a higher temperature (typically 70°F or 21°C). This makes Cl. 2 more resistant to brittle fracture, particularly in thick plates, low-temperature startup conditions, or applications where thermal shock is a concern. Cl. 2 is therefore preferred for critical pressure vessels, while Cl. 1 is used in less demanding environments.
How does SA 387 Gr. 22 Cl. 2 compare to carbon steel plates like SA 516 Gr. 70 in high-temperature service?
SA 387 Gr. 22 Cl. 2 is specifically designed for elevated-temperature service, offering superior creep strength, stress-rupture performance, and oxidation resistance compared to SA 516 Gr. 70 carbon steel. SA 516 is typically limited to service temperatures below 400°C, whereas SA 387 Gr. 22 can operate reliably up to 593°C. In refinery and petrochemical applications, SA 387 Gr. 22 is used for furnace tubes, reactor shells, and heat exchanger components, while SA 516 is used for lower-temperature pressure vessels and storage tanks.
What are the strength differences between SA 387 Gr. 22 Cl. 2 and SA 387 Gr. 22 Cl. 1?
While the tensile and yield strength requirements for Cl. 1 and Cl. 2 are nearly identical, Cl. 2 has more stringent impact toughness requirements. This means that Cl. 2 plates must undergo additional testing to ensure they maintain toughness at lower temperatures, which is critical for thick-walled structures and applications where safety is paramount. The improved toughness of Cl. 2 also provides better resistance to fatigue and thermal shock, making it the preferred choice for critical pressure equipment.